Extension cord connector



APril 1957 R. A. FISCHER ETAL 3,315,213

EXTENSION CORD CONNECTOR I Filed June 26, 1964 R S Rm; m3 wHW m R 5 mm AD W M Rwfl V: B

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United States Patent 3,315,213 EXTENSION CORD CONNECTOR Ronald A. Fischer and Adolph R. Fischer, both of 5801 E. 17th St., Indianapolis, Ind. 46218 Filed June 26, 1964, Ser. No. 378,256

3 Claims. (Cl. 339-92) For example, in building construction projects, many extension cords are frequently connected together in order to supply power to electrically driven hand tools at various locations on the construction site. However, because of long runs of cord, there are many plug and socket joints in a series of cords, which can be pulled apart if a workman pulls on the cord during the use of a tool. Also it sometimes happens that boards and other building construction materials are dragged across cords or workmen trip over cords, all of which tend to separate the usual attachments.

Frequently it is not immediately apparent where the extension cords have been pulled apart, and a connsiderable amount of down time results. This not only delays the work, but raises construction costs.

It is therefore a general object of the present invention to provide a device readily attachable to conventional extension cords and permitting a whole series of cords to be connected together reliably so that they cannot be pulled apart.

A further object is to provide such a device which can be easily and inexpensively manufactured.

Described briefly, a typical embodiment of the present invention employs a casing made of electrically non-conductive material and having a pair of biased contactors near one end thereof exposed in a longitudinally extending opening therein. The two wires of one extension cord are connected to these contactors.

A core is fittingly and slidingly received in the other end of the casing, and the core has resiliently biased connector strips therein disposed to engage the contactors of the casing when the core is properly inserted. The rear ends of the connector strips are connected to the wires of a second extension cord.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIG. 1 is a side elevational view of a typical embodiment of the present invention, with a portion being broken away to show the electrical contacting arrangement of the contactor in the casing with one contactor of the core.

FIG. 2 is a right hand end view of the embodiment in FIG. 1.

FIG. 3 is a left hand end view thereof.

FIG. 4 is a top plan view of the core thereof, removed from the casing.

FIG. 5 is a section through the core taken along the line 5-5 in FIG. 2 and viewed in the direction of the arrows.

Referring now to the drawings in detail, the casing is made up of two, identical upper and lower halves 11 and 12, each having four vertically extending apertures 13, 14, 16, and 17, through which the tie bolts 18 and 19 are provided to secure the halves together with their faces abutting at a parting line 21. Each of these halves is channel shaped, with the upper half having a central Wall 22 and a pair of horizontally spaced side walls 23 and 24 in horizontally spaced parallel relationship. Also "ice each half has a centrally located semi-circular groove in the side wall thereof at the parting line to receive the shank of a thumb screw 26, whose purpose will become apparent as the description proceeds.

As shown in FIG. 3, the upper half of the casing has a recess 27 in the center wall 22 of the channel therein, the recess extending from the front end 28 of the housing rearwardly toward the rear end. A like recess 29 is provided in the lower half of the casing and an electrical contactor 30 is provided therein, this contactor having a portion 31 having a threaded aperture therethrough receiving the screw 32, and having an inwardly projecting portion 33 which forms an abutment surface 34, and having a portion 36 projecting rearwardly from the abutment portion, and a further portion 37 molded into the case at the rear of the recess 29. The portion 36 has a detent aperture 38 therein and has a resilient biasing block 39 thereunder. This block provides an inward bias on this portion of the contactor. A like contactor 41 is provided at the upper half of the casing in the same manner.

The first extension cord 42 has two wires 43 and 44, wire 43 being connected to the contactor portion 31 by the screw fastener 32. If desired, threads can also be provided in the casing as shown for engagement by the screw 32.

An elongated core 46 of rectangular cross-section is fit tingly and slidingly received in the longitudinal opening in the casing which is formed by the two casing halves. As shown in FIG. 3, the core 46 has a recess 47 in the upper surface thereof at the front end thereof and a recess 48 in the lower face thereof at the front end thereof. As shown in FIG. 2, recesses 49 and 51 are provided in the upper and lower faces of the core at the rear end thereof. As shown in FIG. 5, a terminal strip 57 is molded into the core'extending between the recess 47 and the recess 49. A like terminal strip is provided between the lower front and rear recesses.

The purpose of the terminal strips is to provide means for making an electrical connection between the wires 53 and 54 of extension cord 56 and the contactors in the casing. The terminal strip 57 may have a threaded aperture in the rear end thereof receiving the screw 69. The front end thereof is upwardly turned in the recess 47 with the upstanding portion 59, (FIG. 5) and a portion 61 projects forwardly therefrom (FIG. 4). It is this portion 61 together with the detent button 62 which contact the upper contactor in the casing. In the same way, the lower terminal strip 63 (FIG. 1) has a downwardly extending portion 64 in the recess 48 and the forwardly extending portion 66 with a projection 67 therein received in the detent aperture 38 in the lower contactor of the casing. A resilient block 68 is provided in the core between the core and the portion 66 of the contactor strip therein to add a resilient bias holding the contacting portions of the two lower contactors together so that a good electrical connection is made. The same arrangement is provided between the portion 61 of the upper contactor of the core and the upper contactor of the case.

At the rear end of the core, in the recesses 49 and 51, connection of the extension cord wires 53 and 54 to the lower and upper terminal strips, respectively, is achieved by the use of the fastening screws 69 and 71. So it is seen that when the core and case are in assembly with the front end of the core abutting the abutment portions of the front contactors of the casing, complete electrical paths are made between the wires of extension cord 42 and those of extension cord 56.

In order to securely attach the extension cord outer covering to the core and casing, prongs are molded into the core and the casing. The prongs 76 and 77 for the casing, have apertures 78 and 79 respectively therein (FIG. 1) receiving screws 80 attaching the cable-pinch- 3 ing clamps 81 and 82 thereto (FIG. 3). Two sets of screws, and extra long or double clamps are used as shown to positively secure the extension cord to the casing.

A similar arrangement is provided in the core where the prongs 83 and 84 extend from the rear end thereof and have apertures 86 and 87 therein receiving clamp mounting screws.

In order to securely maintain the position of the core in the casing so that electrical contact is assured at all times, the thumb screw 26 is threadedly received in the core and the shank thereof passes through semicircular transverse grooves in the walls of the upper and lower casing halves at their abutting faces. This prevents the core from coming out.

The construction of the present invention is such that the electrically conductive parts need not be bolted into any of the parts but can be easily slid into the openings provided therefor and secured by the screws. This is because of the size and shape of the openings and of the strips and contactors. The contactors in either the core or the casing can be readily replaced by simply separating the core from the casing and, if the contactors in the casingare to be replaced, the tie-bolts can be disconnected so the casing halves can be separated.

From the foregoing description, it is believed apparent that the present invention is well suited to achievement of the objects set out herein and to providing advantages not specifically mentioned.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. An extension cord device comprising:

an elongated casing of dielectric material, said casing having upper and lower identical casing halves, the two halves being placed together in abutting relationship;

fasteners securing said two halves together, said two halves, when assembled together, providing an elongated rectangular opening therethrough, with each half having a pair of horizontally spaced side walls and a central wall extending between said side walls, said side walls and central walls forming said rectangular opening, the central wall of each of said halves having a centrally located cut-out therein extending from one end of the half toward the other end,

first and second resilient electrically conductive contactors, each having a portion received in said cutout of one of the two halves, and each having an inwardly projecting portion providing an abutment and a portion projecting therefrom toward the other end of said casing and having a detent aperture therein, the detent apertured portion having a resilient block disposed between the apertured portion and the bottom of the cutout;

and a cable clamp mount having a portion projecting forwardly from the front end of the casing and having a portion molded into said casing;

an extension cord wire contacting said contactor in said cut-out;

and a fastener screw securing said extension cord wire and said contactor in said casing to establish electric connection between said wire and said contactor; an elongated substantially solid core of dielectric material, said core being fittingly and non-rotatingly received in said rectangular opening in said casing, said core having upper and lower cut-outs in the front end thereof and upper and lower openings extending from said upper and lower cut-outs, re-

spectively to upper and lower cut-outs in the rear end of said core;

and upper and lower spring connector strips, said upper strip having a forward end with a detent projection therein disposed in a cut-out in the forward end of said core and resiliently biased against the first contactor in said casing and having a front end abuttingly engaging the stop portion of said first connector of said casing to limit the travel of said core toward the front end of said casing, and said lower connector strip having a detent projection bearing portion in the front end thereof received in the detent aperture in the second contactor in said casing and abuttingly engaging the stop portion of said second contactor, the rear end of each of said contact strips in said core being secured in the cut-outs in the rear end of said core;

a pair of rearwardly projecting cable clamp mounting prongs having portion molded into said core;

and an extension cord secured to said connector strips;

a thumb bolt extending through semicircular grooves in the abutting faces of said casing halves and threadedly received in said core and preventing removal of said core from said casing, whereby an intact and tensile load withstanding electrical connection is made between the extension cord wires attached to said core, the prongs at the front end of said casing and at the rear end of said core being extra long spaced to receive extension cord therebetween, and each prong having a pair of screws securing an extra length of cable clamping means thereto, said clamps thereupon tightly pinching said extension cords there between.

2. An extension cord device comprising:

an elongated casing of dielectric material, said casing having upper and lower casing members;

the two members being secured together in abutting relationship, said two members, when assembled together, providing an elongated opening therethrough, with each member having a wall with a recess therein; 7

first and second resilient electrically conductive contactors, each having a portion received in one of said recesses, and each having a portion at the surface of the wall in which its receiving recess is provided;

a pair of wires of a first extension cord, said wires being fastened to said contactors in said recesses; an elongated core of dielectric material, said core being fittingly received in said opening in said casing, and said core having walls disposed with respect to the walls of said casing in a manner preventing rotation of said core in said casing, said core having upper and lower front recesses in the front end thereof and upper and lower openings extending from said upper and lower front recesses, respectively to rear recesses in the rear end of said core;

and upper and lower spring connector strips, said upper strip having a forward end disposed in the upper recess in the forward end of said core and resiliently biased against the first contactor in said casing, and said lower connector strip having a forward end disposed in the lower recess in the front end of said core and resiliently biased against said second contactor, the rear end of each of said contact strips in said core being disposed in the rear recesses of said core;

a pair of wires of a second extension cord, said wires being fastened to the rear ends of said connector strips;

a manually releasable fastener extending through said casing and into said core and preventing removal of said core from said casing, whereby an intact and tensil load withstanding electrical connection is made between the said first and second extension cords.

3. An extension cord device comprising:

an elongated casing of dielectric material, said casing having two channel shaped casing members, the two members being secured together in abutting relationship with the channel of one facing the channel of the other, thereby providing an elongated opening through the casing;

first and second resilient electrically conductive contactors, each having a portion received in and secured to one of said two casing members, and each having a resiliently supported portion at the opening in said casing;

means in said casing accommodating attachment of extension cord wires to contactors;

an elongated core of dielectric material, said core being fittingly received in said opening in said casing;

third and fourth resilient electrically conductive contactors projecting from said core into contact with said first and second contactors, respectively;

and means in said core disposed for connecting extension cord wires to said third and fourth contactors;

and a manually releasable thumb screw fastener having a shank extending through an aperture in said casing transverse to the direction of reception of said core in said casing, said screw fastener shank being threadedly received in said core and locking said core in said casing, said fastener having only a circular knurled knob projecting outside said casing and its said shank being concealed by said casing and core, thereby minimizing exposure to accidental unlocking, said fastener thereby securing said core in said casing and preventing removal of said core from said casing, whereby an intact and tensile load withstanding electrical connection is made between extension cord wires electrically connected to said first and second contactors and extension cord wires electrically connected to said third and fourth contactors, the said fastener being readily removable manually without tools when desired, to facilitate separation of said core from said casing.

References (Jited by the Examiner UNITED STATES PATENTS 1,536,688 5/1925 Osborn 339- X 2,039,996 5/1936 Hessel 339207 X 2,336,732 12/1943 Howard 339-213 X 2,888,660 5/1959 Fox 339-103 X 3,678,433 2/1963 Sheesley 33975 X FOREIGN PATENTS 733,154 3/1943 Germany.

EDWARD C. ALLEN, Primary Examiner.

W. DONALD MILLER, Examiner. 

2. AN EXTENSION CORD DEVICE COMPRISING: AN ELONGATED CASING OF DIELECTRIC MATERIAL, SAID CASING HAVING UPPER AND LOWER CASING MEMBERS; THE TWO MEMBERS BEING SECURED TOGETHER IN ABUTTING RELATIONSHIP, SAID TWO MEMBERS, WHEN ASSEMBLED TOGETHER, PROVIDING AN ELONGATED OPENING THERETHROUGH, WITH EACH MEMBER HAVING A WALL WITH A RECESS THEREIN; FIRST AND SECOND RESILIENT ELECTRICALLY CONDUCTIVE CONTACTORS, EACH HAVING A PORTION RECEIVED IN ONE OF SAID RECESSES, AND EACH HAVING A PORTION AT THE SURFACE OF THE WALL IN WHICH ITS RECEIVING RECESS IS PROVIDED; A PAIR OF WIRES OF A FIRST EXTENSION CORD, SAID WIRES BEING FASTENED TO SAID CONTACTORS IN SAID RECESSES; AN ELONGATED CORE OF DIELECTRIC MATERIAL, SAID CORE BEING FITTINGLY RECEIVED IN SAID OPENING IN SAID CASING, AND SAID CORE HAVING WALLS DISPOSED WITH RESPECT TO THE WALLS OF SAID CASING IN A MANNER PREVENTING ROTATION OF SAID CORE IN SAID CASING, SAID CORE HAVING UPPER AND LOWER FRONT RECESSES IN THE FRONT END THEREOF AND UPPER AND LOWER OPENINGS EXTENDING FROM SAID UPPER AND LOWER FRONT RECESSES, RESPECTIVELY TO REAR RECESSES IN THE REAR END OF SAID CORE; AND UPPER AND LOWER SPRING CONNECTOR STRIPS, SAID UPPER STRIP HAVING A FORWARD END DISPOSED IN THE UPPER RECESS IN THE FORWARD END OF SAID CORE AND RESILIENTLY BIASED AGAINST THE FIRST CONTACTOR IN SAID CASING, AND SAID LOWER CONNECTOR STRIP HAVING A FORWARD END DISPOSED IN THE LOWER RECESS IN THE FRONT END OF SAID CORE AND RESILIENTLY BIASED AGAINST SAID SECOND CONTACTOR, THE REAR END OF EACH OF SAID CONTACT STRIPS IN SAID CORE BEING DISPOSED IN THE REAR RECESSES OF SAID CORE; A PAIR OF WIRES OF A SECOND EXTENSION CORD, SAID WIRES BEING FASTENED TO THE REAR ENDS OF SAID CONNECTOR STRIPS; A MANUALLY RELEASABLE FASTENER EXTENDING THROUGH SAID CASING AND INTO SAID CORE AND PREVENTING REMOVAL OF SAID CORE FROM SAID CASING, WHEREBY AN INTACT AND TENSILE LOAD WITHSTANDING ELECTRICAL CONNECTION IS MADE BETWEEN THE SAID FIRST AND SECOND EXTENSION CORDS. 